This temple is absolutely wonderful, my favourite place in Osaka. The natural mountain setting is beautiful, and the temple and other structures are obviously well maintained.
The darumas are also charming, and its fun to see them placed around in all sorts of places.

Aside from the aesthetic side, it's really interesting to see all the shrines for the individual deities from Buddhism, and see a place with deep roots in Japanese Buddhism.

I also recommend getting to the temple by hiking or biking - it's a great way to experience nature.